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<head><meta charset="utf-8"><title>edition candidates · edition 2021 · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/index.html">edition 2021</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html">edition candidates</a></h3>

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<a name="225605866"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225605866" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225605866">(Feb 08 2021 at 20:49)</a>:</h4>
<p>Hey all -- so <span class="user-mention" data-user-id="224872">@rylev</span>, <span class="user-mention" data-user-id="310399">@Mara</span> and I got together and pulled together this spreadsheet of <a href="https://docs.google.com/spreadsheets/d/1chZ2SL9T444nvU9al1kQ7TJMwC3IVQQV2xIv1HWGQ_k/edit#gid=0">edition candidates</a></p>



<a name="225605898"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225605898" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225605898">(Feb 08 2021 at 20:49)</a>:</h4>
<p>This is basicaly a list of all the things that could plausibly be changed in the edition</p>



<a name="225605903"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225605903" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225605903">(Feb 08 2021 at 20:49)</a>:</h4>
<p>It's perhaps incomplete</p>



<a name="225605996"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225605996" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225605996">(Feb 08 2021 at 20:50)</a>:</h4>
<p>For each one, we're trying to assign an <strong>owner</strong> and a <strong>liaison</strong> -- the owner is the person doing the work to implement it</p>



<a name="225606044"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225606044" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225606044">(Feb 08 2021 at 20:50)</a>:</h4>
<p>The liaison is some member of the (to be formed) 2021 Edition project group that will be responsible for keeping the status doc up to date</p>



<a name="225606053"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225606053" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225606053">(Feb 08 2021 at 20:50)</a>:</h4>
<p>These can be the same person</p>



<a name="225606151"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225606151" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225606151">(Feb 08 2021 at 20:51)</a>:</h4>
<p>We are shooting to have a list of "viable edition candidates" by March 1st, which will mean that there is an RFC or other kind of formal decision to "do the thing' plus enough of a plan that we believe it is viable</p>



<a name="225606193"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225606193" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225606193">(Feb 08 2021 at 20:51)</a>:</h4>
<p>this roughly means the 1st three columns have a <span aria-label="checkbox" class="emoji emoji-2611" role="img" title="checkbox">:checkbox:</span> or other positive context, not a big red X (<span aria-label="cross mark" class="emoji emoji-274c" role="img" title="cross mark">:cross_mark:</span>)</p>



<a name="225606301"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225606301" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225606301">(Feb 08 2021 at 20:52)</a>:</h4>
<p>As you can see, <span class="user-mention" data-user-id="310399">@Mara</span> is ahead of the game =)</p>



<a name="225608011"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608011" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608011">(Feb 08 2021 at 21:03)</a>:</h4>
<p>Does the red X indicate rejection from inclusion?</p>



<a name="225608075"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608075" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608075">(Feb 08 2021 at 21:04)</a>:</h4>
<p>nope! red X is 'to do' or 'not yet'</p>



<a name="225608129"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608129" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608129">(Feb 08 2021 at 21:04)</a>:</h4>
<p>suggestions for a better emoji are welcome ^^'</p>



<a name="225608155"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608155" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> simulacrum <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608155">(Feb 08 2021 at 21:04)</a>:</h4>
<p>hm, what is the difference with the conversation bubble then? I guess would be good to add a row to the spreadsheet defining this</p>



<a name="225608206"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608206" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608206">(Feb 08 2021 at 21:05)</a>:</h4>
<p>uh, i think the bubble ones have an active conversation going on</p>



<a name="225608323"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608323" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608323">(Feb 08 2021 at 21:06)</a>:</h4>
<p>maybe we should just remove the crosses. they're a bit confusing</p>



<a name="225608454"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608454" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608454">(Feb 08 2021 at 21:07)</a>:</h4>
<p>replaced them with <span aria-label="minus" class="emoji emoji-2796" role="img" title="minus">:minus:</span> for now</p>



<a name="225608590"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225608590" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225608590">(Feb 08 2021 at 21:08)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> hm, is there a difference between  <span aria-label="cross mark" class="emoji emoji-274c" role="img" title="cross mark">:cross_mark:</span> (now <span aria-label="minus" class="emoji emoji-2796" role="img" title="minus">:minus:</span>) and an empty space?</p>



<a name="225609247"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609247" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609247">(Feb 08 2021 at 21:14)</a>:</h4>
<p>there is a key</p>



<a name="225609286"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609286" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609286">(Feb 08 2021 at 21:15)</a>:</h4>
<p><span class="user-mention silent" data-user-id="310399">Mara</span> <a href="#narrow/stream/268952-edition/topic/edition.20candidates/near/225608590">said</a>:</p>
<blockquote>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> hm, is there a difference between  <span aria-label="cross mark" class="emoji emoji-274c" role="img" title="cross mark">:cross_mark:</span> (now <span aria-label="minus" class="emoji emoji-2796" role="img" title="minus">:minus:</span>) and an empty space?</p>
</blockquote>
<p>not really except that it draws your attention to it</p>



<a name="225609291"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609291" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609291">(Feb 08 2021 at 21:15)</a>:</h4>
<p>I think we should have something</p>



<a name="225609303"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609303" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609303">(Feb 08 2021 at 21:15)</a>:</h4>
<p>I don't care <em>too</em> much what it is</p>



<a name="225609312"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609312" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609312">(Feb 08 2021 at 21:15)</a>:</h4>
<p>okay :)</p>



<a name="225609372"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609372" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609372">(Feb 08 2021 at 21:15)</a>:</h4>
<p>there was a key in the google doc but .. not connected very clearly</p>



<a name="225609530"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609530" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609530">(Feb 08 2021 at 21:17)</a>:</h4>
<p>by the way: cells A2 and A3 are styled as links, but don't seem to be actual links.</p>



<a name="225609995"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225609995" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225609995">(Feb 08 2021 at 21:20)</a>:</h4>
<p>yeah i don't know why</p>



<a name="225612107"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225612107" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225612107">(Feb 08 2021 at 21:37)</a>:</h4>
<p>the "dash" <span aria-label="minus" class="emoji emoji-2796" role="img" title="minus">:minus:</span> kind of looks like "N/A" to me</p>



<a name="225612152"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225612152" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225612152">(Feb 08 2021 at 21:37)</a>:</h4>
<p>what about <span aria-label="memo" class="emoji emoji-1f4dd" role="img" title="memo">:memo:</span></p>



<a name="225612167"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225612167" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225612167">(Feb 08 2021 at 21:37)</a>:</h4>
<p><a href="https://emojipedia.org/memo/">https://emojipedia.org/memo/</a></p>



<a name="225614082"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225614082" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225614082">(Feb 08 2021 at 21:52)</a>:</h4>
<p>I made it <span aria-label="pencil" class="emoji emoji-270f" role="img" title="pencil">:pencil:</span> and I added a Key tab</p>



<a name="225645563"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225645563" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Lokathor <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225645563">(Feb 09 2021 at 04:40)</a>:</h4>
<p>"replace rustc_args_required_const with const generics"</p>
<p>this one is certainly possible, but as was mentioned in the "remove #![crate_type]" topic, this doesn't let us remove the old versions, so we don't actually get to remove that from the compiler</p>



<a name="225645758"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225645758" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225645758">(Feb 09 2021 at 04:45)</a>:</h4>
<p>I'd be happy with just bringing libcore's compile times back down</p>



<a name="225646159"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646159" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Lokathor <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646159">(Feb 09 2021 at 04:55)</a>:</h4>
<p>but it wouldn't really? All those old functions still have to exist, no matter what, for all time.</p>



<a name="225646239"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646239" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646239">(Feb 09 2021 at 04:58)</a>:</h4>
<p><a href="https://github.com/rust-lang/rust/pull/79131">https://github.com/rust-lang/rust/pull/79131</a> landed in 1.50, so there's still time to revert the avx512 change</p>



<a name="225646281"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646281" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Joshua Nelson <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646281">(Feb 09 2021 at 04:58)</a>:</h4>
<p>I mean, we'd have to get <em>on</em> it, but I think there's time</p>



<a name="225646293"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646293" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Lokathor <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646293">(Feb 09 2021 at 04:58)</a>:</h4>
<p>well anything not yet stable can be held back, yes</p>



<a name="225646309"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646309" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Lokathor <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646309">(Feb 09 2021 at 04:58)</a>:</h4>
<p>but for anything already stable, since they're in the standard library of the 2k15 and 2k18 editions, they must forever be supported for crates of those editions, but since most people don't build their own core, we'd have to always pre-build those old edition stuff.</p>



<a name="225646316"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225646316" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Lokathor <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225646316">(Feb 09 2021 at 04:59)</a>:</h4>
<p>anyone using -Zbuild-std would get a speed boost :P</p>



<a name="225665670"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225665670" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225665670">(Feb 09 2021 at 09:56)</a>:</h4>
<p>Are we saying the RFC should be accepted by Mar 1? That seems like a pretty tight deadline?</p>



<a name="225665730"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225665730" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225665730">(Feb 09 2021 at 09:56)</a>:</h4>
<p>Or is it enough that there is an RFC with no substantial open concerns</p>



<a name="225665761"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225665761" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225665761">(Feb 09 2021 at 09:57)</a>:</h4>
<p>(I'm contemplating taking ownership of the prelude update if no libs team members want to take it)</p>



<a name="225674278"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225674278" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225674278">(Feb 09 2021 at 11:21)</a>:</h4>
<p><span class="user-mention" data-user-id="226095">@Dirkjan Ochtman</span> it should be obvious by march 1st that the thing is going to happen. so no major blockers etc. that doesn't necessarily mean the rfc is merged yet. in case of the prelude, i don't really expect any issues, as the implementation should be quite simple. but a concrete list of things that should and should not go in there, potential issues, and any lints we'd need for migration, should be reasonable by the end of the month.</p>



<a name="225674410"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225674410" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225674410">(Feb 09 2021 at 11:22)</a>:</h4>
<p><span class="user-mention silent" data-user-id="226095">Dirkjan Ochtman</span> <a href="#narrow/stream/268952-edition/topic/edition.20candidates/near/225665761">said</a>:</p>
<blockquote>
<p>(I'm contemplating taking ownership of the prelude update if no libs team members want to take it)</p>
</blockquote>
<p>if you want to take ownership of that, that'd would be wonderful. the ideas for what to put in the new prelude are a bit all over the place right now (on zulip, github, maybe other places), and nobody has taken ownership of it yet.</p>



<a name="225999921"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225999921" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225999921">(Feb 11 2021 at 14:41)</a>:</h4>
<p>I agree with <span class="user-mention" data-user-id="310399">@Mara</span> -- what I want is that there is a real, actionable plan</p>



<a name="225999933"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/225999933" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#225999933">(Feb 11 2021 at 14:41)</a>:</h4>
<p>and general agreement by the relevant team on that plan</p>



<a name="226307013"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226307013" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226307013">(Feb 14 2021 at 14:32)</a>:</h4>
<p>Has there been any discussion on changing the <code>?</code> desugaring from using <code>From</code> to using <code>Into</code> for the next edition?</p>



<a name="226308819"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226308819" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226308819">(Feb 14 2021 at 15:12)</a>:</h4>
<p><span class="user-mention" data-user-id="211727">@Jonas Schievink</span> there's a much bigger discussion going now about <code>Try</code>/<code>?</code>: <a href="https://github.com/scottmcm/rfcs/blob/do-or-do-not/text/0000-try-trait-v2.md#summary">https://github.com/scottmcm/rfcs/blob/do-or-do-not/text/0000-try-trait-v2.md#summary</a></p>



<a name="226308845"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226308845" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Mara <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226308845">(Feb 14 2021 at 15:13)</a>:</h4>
<p>(but not as part of an edition change)</p>



<a name="226308847"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226308847" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226308847">(Feb 14 2021 at 15:13)</a>:</h4>
<p>Ah, right. Thanks!</p>



<a name="226321013"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226321013" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226321013">(Feb 14 2021 at 19:40)</a>:</h4>
<p>Note that said RFC would make it <em>much</em> harder to change to <code>Into</code>, so if that's something that we want to do, you should definitely run it up the flagpole.</p>



<a name="226321026"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226321026" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226321026">(Feb 14 2021 at 19:41)</a>:</h4>
<p>(At the same time, it would make it much easier to make a <em>different</em> type that used <code>Into</code> instead of <code>From</code> for error-conversion.)</p>



<a name="226324203"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226324203" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226324203">(Feb 14 2021 at 20:52)</a>:</h4>
<p>I was under the impression that <code>?</code> using <code>From</code> is a historical accident and there was desire to change it to <code>Into</code>, but I might be mistaken.</p>



<a name="226324229"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226324229" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Jonas Schievink  [he/him] <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226324229">(Feb 14 2021 at 20:53)</a>:</h4>
<p>But I don't personally have much time to invest here, I just wanted to see if it was considered for the next edition (or at all)</p>



<a name="226325834"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226325834" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226325834">(Feb 14 2021 at 21:31)</a>:</h4>
<p>There was definitely a desire, but IIRC it was tried and broke inference pretty widely.</p>
<p>So I don't know that anyone's ever had a strong enough desire to really push through the work to do the switch.  I suspect that the lint for "this is working but won't in the next edition with <code>Into</code>" would be quite annoying to write, for one...</p>



<a name="226325999"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226325999" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226325999">(Feb 14 2021 at 21:34)</a>:</h4>
<p>That said, I'm pretty sure it's "just" inference breakage, so it's allowed even without an edition if there's a way to get the impact low enough.</p>
<p>It reminds me of the <code>as_ref</code> breakage, actually.  Could be nice to have a generally-applicable lint about "this is only working because there's only one implementation, but is fragile, so you should probably type-annotate something".</p>



<a name="226327785"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226327785" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226327785">(Feb 14 2021 at 22:04)</a>:</h4>
<p>What's the pattern for which it breaks inference?</p>



<a name="226327830"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226327830" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226327830">(Feb 14 2021 at 22:04)</a>:</h4>
<p>Doing that on an edition boundary seems potentially reasonable, if there's sufficient value to doing so.</p>



<a name="226328188"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226328188" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> bstrie <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226328188">(Feb 14 2021 at 22:07)</a>:</h4>
<p>Is there still actual demand for using <code>Into</code> in <code>?</code>? I thought that all the <code>From</code>/<code>Into</code> tension was resolved by the expanded orphan rules (covering, etc.)</p>



<a name="226337302"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226337302" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> cuviper <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226337302">(Feb 15 2021 at 01:39)</a>:</h4>
<p>I attempted <code>Into</code> in <a href="https://github.com/rust-lang/rust/issues/60796">#60796</a>, which very quickly showed ugly inference issues.</p>



<a name="226339329"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/226339329" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#226339329">(Feb 15 2021 at 02:26)</a>:</h4>
<p>Ah, here's a comment from Niko about <em>why</em> this is happening: <a href="https://github.com/rust-lang/rust/issues/38751#issuecomment-616573959">https://github.com/rust-lang/rust/issues/38751#issuecomment-616573959</a></p>



<a name="228233718"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/228233718" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Daniel Henry-Mantilla <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#228233718">(Mar 01 2021 at 13:59)</a>:</h4>
<p>Hey, I apologise if the info is available somewhere and I just somehow missed it; but <strong>what's the update on the inherent <code>.not()</code> method on <code>bool</code>?</strong> There was a hackmd somewhere I just can't find, and I don't see mentions of it except in the "new traits into the prelude" RFC which advocates for the inherent method approach rather than bringing <code>ops::Not</code>. Was it deemed not edition-boundary worthy because, as an inherent method addition, it does not strictly <em>require</em> a new edition to be added?</p>



<a name="228304909"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/228304909" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#228304909">(Mar 01 2021 at 20:59)</a>:</h4>
<p>It's mentioned in <a href="https://github.com/rust-lang/rfcs/pull/3090">https://github.com/rust-lang/rfcs/pull/3090</a></p>



<a name="228304928"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/228304928" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#228304928">(Mar 01 2021 at 20:59)</a>:</h4>
<p>but you already saw that</p>



<a name="228305082"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/268952-edition%202021/topic/edition%20candidates/near/228305082" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Dirkjan Ochtman <a href="https://rust-lang.github.io/zulip_archive/stream/268952-edition-2021/topic/edition.20candidates.html#228305082">(Mar 01 2021 at 21:00)</a>:</h4>
<p>an inherent impl method wouldn't need an RFC/edition boundary  as far as I can tell, just an implementation and a tracking issue for stabilization</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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